Plasmonic fluorescence enhancement of poly(3-hexylthiophene) for organic solar cell applications
- WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
- Jacklyn Claraine Bush (Creator)
- Institution
- Western Carolina University (WCU )
- Web Site: http://library.wcu.edu/
- Advisor
- David Evanoff, Jr.
Abstract: Solar cells are becoming an attractive alternative energy source considering the
need to lessen dependence on nonrenewable energy sources such as fossil fuels. Organic
photovoltaics (PVs) are inexpensive to produce, flexible, and eliminate many potential
environmental hazards. However, organic solar cells are greatly limited in their capacity
to efficiently convert sunlight into usable energy.
Herein, an approach to increase the efficiency of exciton formation of poly(3-
hexylthiophene) (P3HT), a common polymer used in organic solar cell devices, is
described. This enhancement occurred by adding silver nanoparticles to the polymer
surface. The metal nanoparticles cause an increased exciton excitation rate within the
polymer through a mechanism known as surface-enhanced fluorescence (SEF).
Specifically, P3HT fluorescence is increased when molecules are within the near fields of
a metallic nanoparticle under plasmon resonance conditions. Theoretically, the
enhancement of polymer exciton formation should correlate to heightened efficiency
when utilized within a PV device.
Silver nanoparticles are an attractive choice for SEF, as these particles possess
strongly scattering local fields, a highly-polarizing, non-radiative field that extends deep
into the particles' environment, and a plasmon resonance that overlaps well with both the absorption of P3HT and the solar spectrum maximum. In this study, silver nanoparticles
with diameters of 15-153 nm have been synthesized in order to optimize the fluorescence
enhancement factor of P3HT films of comparable thickness to those used in organic solar
cells.
Another aspect of this work was the development of a basic and reliable
methodology for the preparation and analysis of P3HT/silver films. This standard
protocol allows for the future application of our findings into actual devices and is vital
considering the lack of current literature reporting studies of fluorescence effects
produced from particles in this size range.
It was determined that the addition of silver nanoparticles to the P3HT surface
produced a significant increase in fluorescence. Also observed were higher enhancement
factors associated with increasing nanoparticle diameter due to the scattering properties
associated with larger particles. The enhancement associated with increasing particle
size occurred independently of spin-coating speed of the polymer or silver nanoparticle
concentration, though additional studies in the future are required for better methods of
P3HT film deposition and the accurate measurement of particles underneath the polymer
layer. Once enhancement parameters are optimized, studies will also include the
incorporation of these particles into a device.
Plasmonic fluorescence enhancement of poly(3-hexylthiophene) for organic solar cell applications
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Created on 3/1/2012
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Additional Information
- Publication
- Thesis
- Language: English
- Date: 2012
- Keywords
- Nanoparticle, Plasmon Resonance, Poly(3-hexylthiophene), Silver, Solar Cell, Surface-Enhanced Fluorescence
- Subjects
- Solar cells